/*
* Copyright 2003-2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.collections.set;
import java.util.Comparator;
import java.util.SortedSet;
import org.apache.commons.collections.Predicate;
/**
* Decorates another <code>SortedSet</code> to validate that all additions
* match a specified predicate.
* <p>
* This set exists to provide validation for the decorated set.
* It is normally created to decorate an empty set.
* If an object cannot be added to the set, an IllegalArgumentException is thrown.
* <p>
* One usage would be to ensure that no null entries are added to the set.
* <pre>SortedSet set = PredicatedSortedSet.decorate(new TreeSet(), NotNullPredicate.INSTANCE);</pre>
* <p>
* This class is Serializable from Commons Collections 3.1.
*
* @since Commons Collections 3.0
* @version $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
*
* @author Stephen Colebourne
* @author Paul Jack
*/
public class PredicatedSortedSet extends PredicatedSet implements SortedSet {
/** Serialization version */
private static final long serialVersionUID = -9110948148132275052L;
/**
* Factory method to create a predicated (validating) sorted set.
* <p>
* If there are any elements already in the set being decorated, they
* are validated.
*
* @param set the set to decorate, must not be null
* @param predicate the predicate to use for validation, must not be null
* @throws IllegalArgumentException if set or predicate is null
* @throws IllegalArgumentException if the set contains invalid elements
*/
public static SortedSet decorate(SortedSet set, Predicate predicate) {
return new PredicatedSortedSet(set, predicate);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
* <p>
* If there are any elements already in the set being decorated, they
* are validated.
*
* @param set the set to decorate, must not be null
* @param predicate the predicate to use for validation, must not be null
* @throws IllegalArgumentException if set or predicate is null
* @throws IllegalArgumentException if the set contains invalid elements
*/
protected PredicatedSortedSet(SortedSet set, Predicate predicate) {
super(set, predicate);
}
/**
* Gets the sorted set being decorated.
*
* @return the decorated sorted set
*/
private SortedSet getSortedSet() {
return (SortedSet) getCollection();
}
//-----------------------------------------------------------------------
public SortedSet subSet(Object fromElement, Object toElement) {
SortedSet sub = getSortedSet().subSet(fromElement, toElement);
return new PredicatedSortedSet(sub, predicate);
}
public SortedSet headSet(Object toElement) {
SortedSet sub = getSortedSet().headSet(toElement);
return new PredicatedSortedSet(sub, predicate);
}
public SortedSet tailSet(Object fromElement) {
SortedSet sub = getSortedSet().tailSet(fromElement);
return new PredicatedSortedSet(sub, predicate);
}
public Object first() {
return getSortedSet().first();
}
public Object last() {
return getSortedSet().last();
}
public Comparator comparator() {
return getSortedSet().comparator();
}
}